U.S. patent application number 17/610342 was filed with the patent office on 2022-07-14 for efficient uplink resource requests in wlan systems.
This patent application is currently assigned to INTERDIGITAL PATENT HOLDINGS, INC.. The applicant listed for this patent is INTERDIGITAL PATENT HOLDINGS, INC.. Invention is credited to Joseph S. Levy, Hanqing Lou, Alphan Sahin, Li-Hsiang Sun, Xiaofei Wang, Rui Yang.
Application Number | 20220225323 17/610342 |
Document ID | / |
Family ID | |
Filed Date | 2022-07-14 |
United States Patent
Application |
20220225323 |
Kind Code |
A1 |
Wang; Xiaofei ; et
al. |
July 14, 2022 |
EFFICIENT UPLINK RESOURCE REQUESTS IN WLAN SYSTEMS
Abstract
Techniques, devices and systems are disclosed for generating a
resource request poll comprising at least one response criteria,
transmitting the resource request poll, receiving a resource
request report from STAs that meet at least one response criteria.
A trigger frame may be transmitted to the at least one STA based on
the resource request report from the at least one STA. The response
criteria may include at least one of a NFRP, a UL access type, a
delay bound, an NDP feedback report AC, a number of indicated AID
bits, an AID range, an information requested, a number of bits to
be included in NDP feedback report or preamble, number of LTFs to
be included in the NDP feedback report or preamble, and a number of
bits to be included in NDP feedback report or preamble per LTF or
per N LTF symbol.
Inventors: |
Wang; Xiaofei; (North
Caldwell, NJ) ; Lou; Hanqing; (Syosset, NY) ;
Sahin; Alphan; (Westbury, NY) ; Sun; Li-Hsiang;
(San Diego, CA) ; Levy; Joseph S.; (Merrick,
NY) ; Yang; Rui; (Greenlawn, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
INTERDIGITAL PATENT HOLDINGS, INC. |
Wilmington |
DE |
US |
|
|
Assignee: |
INTERDIGITAL PATENT HOLDINGS,
INC.
Wilmington
DE
|
Appl. No.: |
17/610342 |
Filed: |
May 1, 2020 |
PCT Filed: |
May 1, 2020 |
PCT NO: |
PCT/US2020/030993 |
371 Date: |
November 10, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62846031 |
May 10, 2019 |
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International
Class: |
H04W 72/04 20060101
H04W072/04; H04W 72/10 20060101 H04W072/10; H04W 72/08 20060101
H04W072/08; H04W 74/00 20060101 H04W074/00; H04W 74/06 20060101
H04W074/06 |
Claims
1-20. (canceled)
21. A method for wireless communication performed by a station
(STA), the method comprising: receiving, from an access point (AP),
a resource request poll indicating one or more requirements for low
latency traffic and a number of bits that may be included in an
uplink (UL) resource request report; transmitting, to the AP, upon
a determination that a data stream meets the indicated one or more
requirements for low latency traffic, an UL resource request
report, wherein the UL resource request report includes information
within the indicated number of bits, wherein the information
indicates at least one of: an amount of data of the data stream
that is to be transmitted, priority information associated with the
data stream, or a bitmap associating the UL resource request report
with a plurality of traffic priorities; and receiving, from the AP,
a trigger frame in response to the UL resource request report.
22. The method of claim 21, further comprising send, to the AP, a
transmission in response to the received trigger frame.
23. The method of claim 21, wherein the priority information
associated with the data stream indicates at least one Quality of
Service (QoS) requirement.
24. The method of claim 21, wherein the one or more requirements
for low latency traffic comprises at least one of a null data
packet (NDP) feedback report poll (NFRP) type, a UL access type, a
delay bound, an NDP feedback report access category (AC), a number
of indicated AID bits, an AID range, an information requested, or a
number of long training fields (LTFs) to be included in the NDP
feedback report or preamble.
25. The method of claim 21, wherein the resource request poll
comprises non-sequential AIDS associated with a plurality of
STAs.
26. The method of claim 21, wherein the UL resource request report
comprises at least one of an NFRP, an NDP feedback report parameter
set element, or a short resource request poll.
27. A station (STA) comprising: a processor; and a transceiver; the
transceiver configured to receive, from an access point (AP), a
resource request poll indicating one or more requirements for low
latency traffic and a number of bits that may be included in an
uplink (UL) resource request report; the processor and the
transceiver configured to transmit, to the AP, upon a determination
that a data stream meets the indicated one or more requirements for
low latency traffic, an UL resource request report, wherein the UL
resource request report includes information within the indicated
number of bits, wherein the information indicates at least one of:
an amount of data of the data stream that is to be transmitted,
priority information associated with the data stream, or a bitmap
associating the UL resource request report with a plurality of
traffic priorities; and the transceiver configured to receive, from
the AP, a trigger frame in response to the UL resource request
report.
28. The STA of claim 27, the transmitter further configured to
send, to the AP, a transmission in response to the received trigger
frame.
29. The STA of claim 27, wherein the priority information
associated with the data stream indicates at least one Quality of
Service (QoS) requirement.
30. The STA of claim 27, wherein the one or more requirements for
low latency traffic comprises at least one of a null data packet
(NDP) feedback report poll (NFRP) type, a UL access type, a delay
bound, an NDP feedback report access category (AC), a number of
indicated AID bits, an AID range, an information requested, or a
number of long training fields (LTFs) to be included in the NDP
feedback report or preamble.
31. The STA of claim 27, wherein the resource request poll
comprises non-sequential AIDs associated with a plurality of
STAs.
32. The STA of claim 27, wherein the UL resource request report
comprises at least one of an NFRP, an NDP feedback report parameter
set element, or a short resource request poll.
33. The STA of claim 27, wherein the UL resource request report
includes an association ID (AID) associated with the STA.
34. An access point (AP) comprising: a processor; and a
transceiver; the transceiver configured to transmit a resource
request poll indicating one or more requirements for low latency
traffic and a number of bits that may be included in an uplink (UL)
resource request report; the transceiver further configured to
receive, from at least one station (STA), at least one UL resource
request report, wherein the at least one UL resource request report
includes information within the indicated number of bits, wherein
the information indicates at least one of: an amount of data of the
data stream that is to be transmitted, priority information
associated with the data stream, or a bitmap associating the at
least one UL resource request report with a plurality of traffic
priorities; and the transceiver configured to transmit to one or
more of the at least one STAs, a trigger frame in response to the
at least one UL resource request report.
35. The AP of claim 34, wherein the transceiver is configured to
receive at least one transmission in response to the transmitted
trigger frame.
36. The AP of claim 34, wherein the priority information associated
with the data stream indicates at least one Quality of Service
(QoS) requirement.
37. The AP of claim 34, wherein the one or more requirements for
low latency traffic comprises at least one of a null data packet
(NDP) feedback report poll (NFRP) type, a UL access type, a delay
bound, an NDP feedback report access category (AC), a number of
indicated AID bits, an AID range, an information requested, or a
number of long training fields (LTFs) to be included in the NDP
feedback report or preamble.
38. The AP of claim 34, wherein the resource request poll comprises
non-sequential AIDS associated with a plurality of STAs.
39. The AP of claim 34, wherein the UL resource request report
comprises at least one of an NFRP, an NDP feedback report parameter
set element, or a short resource request poll.
40. The AP of claim 34, wherein the UL resource request report
includes at least one association ID (AID) associated with the at
least one STA.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 62/846,031, filed May 10, 2019 the contents of
which are incorporated herein by reference.
BACKGROUND
[0002] Latency is generally referred to as the delay before a
transfer of data begins following an instruction or request for
transfer of the data. Lower latency uplink transmissions can be
supported by a fast exchange of resource requests and/or responses
between an access point (AP) and one or more stations (STAs).
During a null data packet (NDP) feedback report procedure, an AP
may transmit an NDP feedback report poll (NFRP) trigger, in which
the AP may indicate that feedback type is a resource request. A
starting association ID (AID) field may be included in the trigger
frame sent by the AP. Next, an STA may receive and/or detect the
NFRP trigger to determine if it is scheduled and how to transmit
its NDP feedback report. The STA may obtain an NDP feedback report
parameter from management frames. Upon receipt of data from the
STA, an AP may not send an acknowledgement messageto the STAs.
[0003] However, the NDP feedback report procedure may not be
sufficient for certain low latency applications. For example, an AP
may trigger a set of STAs with continuous AIDs, within an AID
range, to transmit a resource request. However, a STA which is not
in the AID range cannot be used to transmit a resource request or
NDP feedback report. Further, a feedback status carried in the in
the NDP feedback report may only signal the buffer size roughly in
bytes. No latency or other quality of service (QoS) requirements
may be included.
SUMMARY
[0004] Techniques, devices, and systems are disclosed for
generating a resource request poll comprising at least one response
criteria, transmitting the resource request poll, receiving a
resource request report from each of at least one station (STA) of
a plurality of associate STAs that meet at least one response
criteria. Further, transmitting a trigger frame to the at least one
STA based on the resource request report from the at least one STA
is disclosed.
[0005] Transmitting the resource request poll, as disclosed, may
include one of broadcasting and multicasting the resource request
poll. The response criteria includes at least one of a null data
packet (NDP) feedback report poll (NFRP) type, an uplink (UL)
access type, a delay bound, an NDP feedback report access category
(AC), a number of indicated AID bits, an AID range, an information
requested, a number of bits to be included in NDP feedback report
or preamble, number of long training fields (LTFs) to be included
in the NDP feedback report or preamble, and a number of bits to be
included in NDP feedback report or preamble per LTF or per N LTF
symbol. The delay bound may include an amount of time and an AC may
be selected from at least one of a Low Latency, a best effort (BK),
a background (BC), a video (VI), and a voice (VO). At least one of
the resource request poll and the trigger frame may be transmitted
during a target wake up time (TWT). The resource request poll may
include non-sequential STA AIDs. The resource request poll may
include one of an element, a NDP feedback report parameter set
element, and a short resource request poll. Additionally, an
indication may be provided that a resource request report generated
based on the resource request poll is transmitted as one of a
random transmission and a deterministic transmission. Additionally,
a collision based on two or more resource request reports from two
or more STAs of the plurality of associated STAs may be
detected.
[0006] Techniques, devices, and systems are disclosed for receiving
a resource request poll comprising at least one response criteria,
determining that a data stream meets the at least one response
criteria, generating a resource request report based on the at
least one response criteria, transmitting the resource request
report to an AP, and receiving a trigger frame from the AP based on
the resource request report.
[0007] Further, generating the resource request may include
generating a preamble and N bits based on the response criteria.
The response criteria may include at least one of a null data
packet (NDP) feedback report poll (NFRP) type, an uplink (UL)
access type, a delay bound, an NDP feedback report access category
(AC), a number of indicated AID bits, an AID range, an information
requested, a number of bits to be included in NDP feedback report
or preamble, number of long training fields (LTFs) to be included
in the NDP feedback report or preamble, and a number of bits to be
included in NDP feedback report or preamble per LTF or per N LTF
symbol. The resource request poll may include non-sequential STA
AIDs and the resource request report may include one of an NFRP, a
NDP feedback report parameter set element, and a short resource
request poll. Additionally, generating the resource request report
may include inserting an STA association ID (AID) into the resource
request report.
[0008] A wireless transmit receive unit (WTRU) is disclosed and is
configured to receive a resource request poll comprising at least
one response criteria, determine that a data stream meets the at
least one response criteria, generate a resource request report
based on the at least one response criteria, transmit the resource
request report to an AP, and receive a trigger frame from the AP.
The WTRU may be configured to transmit a UL data transmission based
on the trigger frame. The UL data transmission may include low
latency data. The response criteria may include at least one of a
null data packet (NDP) feedback report poll (NFRP) type, an uplink
(UL) access type, a delay bound, an NDP feedback report access
category (AC), a number of indicated AID bits, an AID range, an
information requested, a number of bits to be included in NDP
feedback report or preamble, number of long training fields (LTFs)
to be included in the NDP feedback report or preamble, and a number
of bits to be included in NDP feedback report or preamble per LTF
or per N LTF symbol.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] A more detailed understanding may be had from the following
description, given by way of example in conjunction with the
accompanying drawings, wherein like reference numerals in the
figures indicate like elements, and wherein:
[0010] FIG. 1A is a system diagram illustrating an example
communications system in which one or more disclosed embodiments
may be implemented;
[0011] FIG. 1B is a system diagram illustrating an example wireless
transmit/receive unit (WTRU) that may be used within the
communications system illustrated in FIG. 1A according to an
embodiment;
[0012] FIG. 1C is a system diagram illustrating an example radio
access network (RAN) and an example core network (CN) that may be
used within the communications system illustrated in FIG. 1A
according to an embodiment;
[0013] FIG. 1D is a system diagram illustrating a further example
RAN and a further example CN that may be used within the
communications system illustrated in FIG. 1A according to an
embodiment;
[0014] FIG. 2 shows an example null data packet (NDP) report
procedure;
[0015] FIG. 3 method for low latency resource request indication
and trigger based uplink transmissions;
[0016] FIG. 4 shows a flowchart for implementing AP and STA based
transmission procedures; and
[0017] FIG. 5 shows a diagram of a resource request poll and a
resource request report.
DETAILED DESCRIPTION
[0018] FIG. 1A is a diagram illustrating an example communications
system 100 in which one or more disclosed embodiments may be
implemented. The communications system 100 may be a multiple access
system that provides content, such as voice, data, video,
messaging, broadcast, etc., to multiple wireless users. The
communications system 100 may enable multiple wireless users to
access such content through the sharing of system resources,
including wireless bandwidth. For example, the communications
systems 100 may employ one or more channel access methods, such as
code division multiple access (CDMA), time division multiple access
(TDMA), frequency division multiple access (FDMA), orthogonal FDMA
(OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word
discrete Fourier transform Spread OFDM (ZT-UW-DFT-S-OFDM), unique
word OFDM (UW-OFDM), resource block-filtered OFDM, filter bank
multicarrier (FBMC), and the like.
[0019] As shown in FIG. 1A, the communications system 100 may
include wireless transmit/receive units (WTRUs) 102a, 102b, 102c,
102d, a radio access network (RAN) 104, a core network (CN) 106, a
public switched telephone network (PSTN) 108, the Internet 110, and
other networks 112, though it will be appreciated that the
disclosed embodiments contemplate any number of WTRUs, base
stations, networks, and/or network elements. Each of the WTRUs
102a, 102b, 102c, 102d may be any type of device configured to
operate and/or communicate in a wireless environment. By way of
example, the WTRUs 102a, 102b, 102c, 102d, any of which may be
referred to as a station (STA), may be configured to transmit
and/or receive wireless signals and may include a user equipment
(UE), a mobile station, a fixed or mobile subscriber unit, a
subscription-based unit, a pager, a cellular telephone, a personal
digital assistant (PDA), a smartphone, a laptop, a netbook, a
personal computer, a wireless sensor, a hotspot or Mi-Fi device, an
Internet of Things (IoT) device, a watch or other wearable, a
head-mounted display (HMD), a vehicle, a drone, a medical device
and applications (e.g., remote surgery), an industrial device and
applications (e.g., a robot and/or other wireless devices operating
in an industrial and/or an automated processing chain contexts), a
consumer electronics device, a device operating on commercial
and/or industrial wireless networks, and the like. Any of the WTRUs
102a, 102b, 102c and 102d may be interchangeably referred to as a
UE.
[0020] The communications systems 100 may also include a base
station 114a and/or a base station 114b. Each of the base stations
114a, 114b may be any type of device configured to wirelessly
interface with at least one of the WTRUs 102a, 102b, 102c, 102d to
facilitate access to one or more communication networks, such as
the CN 106, the Internet 110, and/or the other networks 112. By way
of example, the base stations 114a, 114b may be a base transceiver
station (BTS), a NodeB, an eNode B (eNB), a Home Node B, a Home
eNode B, a next generation NodeB, such as a gNode B (gNB), a new
radio (NR) NodeB, a site controller, an access point (AP), a
wireless router, and the like. While the base stations 114a, 114b
are each depicted as a single element, it will be appreciated that
the base stations 114a, 114b may include any number of
interconnected base stations and/or network elements.
[0021] The base station 114a may be part of the RAN 104, which may
also include other base stations and/or network elements (not
shown), such as a base station controller (BSC), a radio network
controller (RNC), relay nodes, and the like. The base station 114a
and/or the base station 114b may be configured to transmit and/or
receive wireless signals on one or more carrier frequencies, which
may be referred to as a cell (not shown). These frequencies may be
in licensed spectrum, unlicensed spectrum, or a combination of
licensed and unlicensed spectrum. A cell may provide coverage for a
wireless service to a specific geographical area that may be
relatively fixed or that may change over time. The cell may further
be divided into cell sectors. For example, the cell associated with
the base station 114a may be divided into three sectors. Thus, in
one embodiment, the base station 114a may include three
transceivers, i.e., one for each sector of the cell. In an
embodiment, the base station 114a may employ multiple-input
multiple output (MIMO) technology and may utilize multiple
transceivers for each sector of the cell. For example, beamforming
may be used to transmit and/or receive signals in desired spatial
directions.
[0022] The base stations 114a, 114b may communicate with one or
more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116,
which may be any suitable wireless communication link (e.g., radio
frequency (RF), microwave, centimeter wave, micrometer wave,
infrared (IR), ultraviolet (UV), visible light, etc.). The air
interface 116 may be established using any suitable radio access
technology (RAT).
[0023] More specifically, as noted above, the communications system
100 may be a multiple access system and may employ one or more
channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA,
and the like. For example, the base station 114a in the RAN 104 and
the WTRUs 102a, 102b, 102c may implement a radio technology such as
Universal Mobile Telecommunications System (UMTS) Terrestrial Radio
Access (UTRA), which may establish the air interface 116 using
wideband CDMA (WCDMA). WCDMA may include communication protocols
such as High-Speed Packet Access (HSPA) and/or Evolved HSPA
(HSPA+). HSPA may include High-Speed Downlink (DL) Packet Access
(HSDPA) and/or High-Speed Uplink (UL) Packet Access (HSUPA).
[0024] In an embodiment, the base station 114a and the WTRUs 102a,
102b, 102c may implement a radio technology such as Evolved UMTS
Terrestrial Radio Access (E-UTRA), which may establish the air
interface 116 using Long Term Evolution (LTE) and/or LTE-Advanced
(LTE-A) and/or LTE-Advanced Pro (LTE-A Pro).
[0025] In an embodiment, the base station 114a and the WTRUs 102a,
102b, 102c may implement a radio technology such as NR Radio
Access, which may establish the air interface 116 using NR.
[0026] In an embodiment, the base station 114a and the WTRUs 102a,
102b, 102c may implement multiple radio access technologies. For
example, the base station 114a and the WTRUs 102a, 102b, 102c may
implement LTE radio access and NR radio access together, for
instance using dual connectivity (DC) principles. Thus, the air
interface utilized by WTRUs 102a, 102b, 102c may be characterized
by multiple types of radio access technologies and/or transmissions
sent to/from multiple types of base stations (e.g., an eNB and a
gNB).
[0027] In other embodiments, the base station 114a and the WTRUs
102a, 102b, 102c may implement radio technologies such as IEEE
802.11 (i.e., Wireless Fidelity (WiFi), IEEE 802.16 (i.e.,
Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000,
CDMA2000 1.times., CDMA2000 EV-DO, Interim Standard 2000 (IS-2000),
Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global
System for Mobile communications (GSM), Enhanced Data rates for GSM
Evolution (EDGE), GSM EDGE (GERAN), and the like.
[0028] The base station 114b in FIG. 1A may be a wireless router,
Home Node B, Home eNode B, or access point, for example, and may
utilize any suitable RAT for facilitating wireless connectivity in
a localized area, such as a place of business, a home, a vehicle, a
campus, an industrial facility, an air corridor (e.g., for use by
drones), a roadway, and the like. In one embodiment, the base
station 114b and the WTRUs 102c, 102d may implement a radio
technology such as IEEE 802.11 to establish a wireless local area
network (WLAN). In an embodiment, the base station 114b and the
WTRUs 102c, 102d may implement a radio technology such as IEEE
802.15 to establish a wireless personal area network (WPAN). In yet
another embodiment, the base station 114b and the WTRUs 102c, 102d
may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE,
LTE-A, LTE-A Pro, NR etc.) to establish a picocell or femtocell. As
shown in FIG. 1A, the base station 114b may have a direct
connection to the Internet 110. Thus, the base station 114b may not
be required to access the Internet 110 via the CN 106.
[0029] The RAN 104 may be in communication with the CN 106, which
may be any type of network configured to provide voice, data,
applications, and/or voice over internet protocol (VoIP) services
to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may
have varying quality of service (QoS) requirements, such as
differing throughput requirements, latency requirements, error
tolerance requirements, reliability requirements, data throughput
requirements, mobility requirements, and the like. The CN 106 may
provide call control, billing services, mobile location-based
services, pre-paid calling, Internet connectivity, video
distribution, etc., and/or perform high-level security functions,
such as user authentication. Although not shown in FIG. 1A, it will
be appreciated that the RAN 104 and/or the CN 106 may be in direct
or indirect communication with other RANs that employ the same RAT
as the RAN 104 or a different RAT. For example, in addition to
being connected to the RAN 104, which may be utilizing a NR radio
technology, the CN 106 may also be in communication with another
RAN (not shown) employing a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or
WiFi radio technology.
[0030] The CN 106 may also serve as a gateway for the WTRUs 102a,
102b, 102c, 102d to access the PSTN 108, the Internet 110, and/or
the other networks 112. The PSTN 108 may include circuit-switched
telephone networks that provide plain old telephone service (POTS).
The Internet 110 may include a global system of interconnected
computer networks and devices that use common communication
protocols, such as the transmission control protocol (TCP), user
datagram protocol (UDP) and/or the internet protocol (IP) in the
TCP/IP internet protocol suite. The networks 112 may include wired
and/or wireless communications networks owned and/or operated by
other service providers. For example, the networks 112 may include
another CN connected to one or more RANs, which may employ the same
RAT as the RAN 104 or a different RAT.
[0031] Some or all of the WTRUs 102a, 102b, 102c, 102d in the
communications system 100 may include multi-mode capabilities
(e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple
transceivers for communicating with different wireless networks
over different wireless links). For example, the WTRU 102c shown in
FIG. 1A may be configured to communicate with the base station
114a, which may employ a cellular-based radio technology, and with
the base station 114b, which may employ an IEEE 802 radio
technology.
[0032] FIG. 1B is a system diagram illustrating an example WTRU
102. As shown in FIG. 1B, the WTRU 102 may include a processor 118,
a transceiver 120, a transmit/receive element 122, a
speaker/microphone 124, a keypad 126, a display/touchpad 128,
non-removable memory 130, removable memory 132, a power source 134,
a global positioning system (GPS) chipset 136, and/or other
peripherals 138, among others. It will be appreciated that the WTRU
102 may include any sub-combination of the foregoing elements while
remaining consistent with an embodiment.
[0033] The processor 118 may be a general purpose processor, a
special purpose processor, a conventional processor, a digital
signal processor (DSP), a plurality of microprocessors, one or more
microprocessors in association with a DSP core, a controller, a
microcontroller, Application Specific Integrated Circuits (ASICs),
Field Programmable Gate Arrays (FPGAs), any other type of
integrated circuit (IC), a state machine, and the like. The
processor 118 may perform signal coding, data processing, power
control, input/output processing, and/or any other functionality
that enables the WTRU 102 to operate in a wireless environment. The
processor 118 may be coupled to the transceiver 120, which may be
coupled to the transmit/receive element 122. While FIG. 1B depicts
the processor 118 and the transceiver 120 as separate components,
it will be appreciated that the processor 118 and the transceiver
120 may be integrated together in an electronic package or
chip.
[0034] The transmit/receive element 122 may be configured to
transmit signals to, or receive signals from, a base station (e.g.,
the base station 114a) over the air interface 116. For example, in
one embodiment, the transmit/receive element 122 may be an antenna
configured to transmit and/or receive RF signals. In an embodiment,
the transmit/receive element 122 may be an emitter/detector
configured to transmit and/or receive IR, UV, or visible light
signals, for example. In yet another embodiment, the
transmit/receive element 122 may be configured to transmit and/or
receive both RF and light signals. It will be appreciated that the
transmit/receive element 122 may be configured to transmit and/or
receive any combination of wireless signals.
[0035] Although the transmit/receive element 122 is depicted in
FIG. 1B as a single element, the WTRU 102 may include any number of
transmit/receive elements 122. More specifically, the WTRU 102 may
employ MIMO technology. Thus, in one embodiment, the WTRU 102 may
include two or more transmit/receive elements 122 (e.g., multiple
antennas) for transmitting and receiving wireless signals over the
air interface 116.
[0036] The transceiver 120 may be configured to modulate the
signals that are to be transmitted by the transmit/receive element
122 and to demodulate the signals that are received by the
transmit/receive element 122. As noted above, the WTRU 102 may have
multi-mode capabilities. Thus, the transceiver 120 may include
multiple transceivers for enabling the WTRU 102 to communicate via
multiple RATs, such as NR and IEEE 802.11, for example.
[0037] The processor 118 of the WTRU 102 may be coupled to, and may
receive user input data from, the speaker/microphone 124, the
keypad 126, and/or the display/touchpad 128 (e.g., a liquid crystal
display (LCD) display unit or organic light-emitting diode (OLED)
display unit). The processor 118 may also output user data to the
speaker/microphone 124, the keypad 126, and/or the display/touchpad
128. In addition, the processor 118 may access information from,
and store data in, any type of suitable memory, such as the
non-removable memory 130 and/or the removable memory 132. The
non-removable memory 130 may include random-access memory (RAM),
read-only memory (ROM), a hard disk, or any other type of memory
storage device. The removable memory 132 may include a subscriber
identity module (SIM) card, a memory stick, a secure digital (SD)
memory card, and the like. In other embodiments, the processor 118
may access information from, and store data in, memory that is not
physically located on the WTRU 102, such as on a server or a home
computer (not shown).
[0038] The processor 118 may receive power from the power source
134, and may be configured to distribute and/or control the power
to the other components in the WTRU 102. The power source 134 may
be any suitable device for powering the WTRU 102. For example, the
power source 134 may include one or more dry cell batteries (e.g.,
nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride
(NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and
the like.
[0039] The processor 118 may also be coupled to the GPS chipset
136, which may be configured to provide location information (e.g.,
longitude and latitude) regarding the current location of the WTRU
102. In addition to, or in lieu of, the information from the GPS
chipset 136, the WTRU 102 may receive location information over the
air interface 116 from a base station (e.g., base stations 114a,
114b) and/or determine its location based on the timing of the
signals being received from two or more nearby base stations. It
will be appreciated that the WTRU 102 may acquire location
information by way of any suitable location-determination method
while remaining consistent with an embodiment.
[0040] The processor 118 may further be coupled to other
peripherals 138, which may include one or more software and/or
hardware modules that provide additional features, functionality
and/or wired or wireless connectivity. For example, the peripherals
138 may include an accelerometer, an e-compass, a satellite
transceiver, a digital camera (for photographs and/or video), a
universal serial bus (USB) port, a vibration device, a television
transceiver, a hands free headset, a Bluetooth.RTM. module, a
frequency modulated (FM) radio unit, a digital music player, a
media player, a video game player module, an Internet browser, a
Virtual Reality and/or Augmented Reality (VR/AR) device, an
activity tracker, and the like. The peripherals 138 may include one
or more sensors. The sensors may be one or more of a gyroscope, an
accelerometer, a hall effect sensor, a magnetometer, an orientation
sensor, a proximity sensor, a temperature sensor, a time sensor; a
geolocation sensor, an altimeter, a light sensor, a touch sensor, a
magnetometer, a barometer, a gesture sensor, a biometric sensor, a
humidity sensor and the like.
[0041] The WTRU 102 may include a full duplex radio for which
transmission and reception of some or all of the signals (e.g.,
associated with particular subframes for both the UL (e.g., for
transmission) and DL (e.g., for reception) may be concurrent and/or
simultaneous. The full duplex radio may include an interference
management unit to reduce and or substantially eliminate
self-interference via either hardware (e.g., a choke) or signal
processing via a processor (e.g., a separate processor (not shown)
or via processor 118). In an embodiment, the WTRU 102 may include a
half-duplex radio for which transmission and reception of some or
all of the signals (e.g., associated with particular subframes for
either the UL (e.g., for transmission) or the DL (e.g., for
reception)).
[0042] FIG. 10 is a system diagram illustrating the RAN 104 and the
CN 106 according to an embodiment. As noted above, the RAN 104 may
employ an E-UTRA radio technology to communicate with the WTRUs
102a, 102b, 102c over the air interface 116. The RAN 104 may also
be in communication with the CN 106.
[0043] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it
will be appreciated that the RAN 104 may include any number of
eNode-Bs while remaining consistent with an embodiment. The
eNode-Bs 160a, 160b, 160c may each include one or more transceivers
for communicating with the WTRUs 102a, 102b, 102c over the air
interface 116. In one embodiment, the eNode-Bs 160a, 160b, 160c may
implement MIMO technology. Thus, the eNode-B 160a, for example, may
use multiple antennas to transmit wireless signals to, and/or
receive wireless signals from, the WTRU 102a.
[0044] Each of the eNode-Bs 160a, 160b, 160c may be associated with
a particular cell (not shown) and may be configured to handle radio
resource management decisions, handover decisions, scheduling of
users in the UL and/or DL, and the like. As shown in FIG. 10, the
eNode-Bs 160a, 160b, 160c may communicate with one another over an
X2 interface.
[0045] The CN 106 shown in FIG. 10 may include a mobility
management entity (MME) 162, a serving gateway (SGW) 164, and a
packet data network (PDN) gateway (PGW) 166. While the foregoing
elements are depicted as part of the CN 106, it will be appreciated
that any of these elements may be owned and/or operated by an
entity other than the CN operator.
[0046] The MME 162 may be connected to each of the eNode-Bs 162a,
162b, 162c in the RAN 104 via an S1 interface and may serve as a
control node. For example, the MME 162 may be responsible for
authenticating users of the WTRUs 102a, 102b, 102c, bearer
activation/deactivation, selecting a particular serving gateway
during an initial attach of the WTRUs 102a, 102b, 102c, and the
like. The MME 162 may provide a control plane function for
switching between the RAN 104 and other RANs (not shown) that
employ other radio technologies, such as GSM and/or WCDMA.
[0047] The SGW 164 may be connected to each of the eNode Bs 160a,
160b, 160c in the RAN 104 via the S1 interface. The SGW 164 may
generally route and forward user data packets to/from the WTRUs
102a, 102b, 102c. The SGW 164 may perform other functions, such as
anchoring user planes during inter-eNode B handovers, triggering
paging when DL data is available for the WTRUs 102a, 102b, 102c,
managing and storing contexts of the WTRUs 102a, 102b, 102c, and
the like.
[0048] The SGW 164 may be connected to the PGW 166, which may
provide the WTRUs 102a, 102b, 102c with access to packet-switched
networks, such as the Internet 110, to facilitate communications
between the WTRUs 102a, 102b, 102c and IP-enabled devices.
[0049] The CN 106 may facilitate communications with other
networks. For example, the CN 106 may provide the WTRUs 102a, 102b,
102c with access to circuit-switched networks, such as the PSTN
108, to facilitate communications between the WTRUs 102a, 102b,
102c and traditional land-line communications devices. For example,
the CN 106 may include, or may communicate with, an IP gateway
(e.g., an IP multimedia subsystem (IMS) server) that serves as an
interface between the CN 106 and the PSTN 108. In addition, the CN
106 may provide the WTRUs 102a, 102b, 102c with access to the other
networks 112, which may include other wired and/or wireless
networks that are owned and/or operated by other service
providers.
[0050] Although the WTRU is described in FIGS. 1A-1D as a wireless
terminal, it is contemplated that in certain representative
embodiments that such a terminal may use (e.g., temporarily or
permanently) wired communication interfaces with the communication
network.
[0051] In representative embodiments, the other network 112 may be
a WLAN.
[0052] A WLAN in Infrastructure Basic Service Set (BSS) mode may
have an Access Point (AP) for the BSS and one or more stations
(STAs) associated with the AP. The AP may have access or an
interface to a Distribution System (DS) or another type of
wired/wireless network that carries traffic in to and/or out of the
BSS. Traffic to STAs that originates from outside the BSS may
arrive through the AP and may be delivered to the STAs. Traffic
originating from STAs to destinations outside the BSS may be sent
to the AP to be delivered to respective destinations. Traffic
between STAs within the BSS may be sent through the AP, for
example, where the source STA may send traffic to the AP and the AP
may deliver the traffic to the destination STA. The traffic between
STAs within a BSS may be considered and/or referred to as
peer-to-peer traffic. The peer-to-peer traffic may be sent between
(e.g., directly between) the source and destination STAs with a
direct link setup (DLS). In certain representative embodiments, the
DLS may use an 802.11e DLS or an 802.11z tunneled DLS (TDLS). A
WLAN using an Independent BSS (IBSS) mode may not have an AP, and
the STAs (e.g., all of the STAs) within or using the IBSS may
communicate directly with each other. The IBSS mode of
communication may sometimes be referred to herein as an "ad-hoc"
mode of communication.
[0053] When using the 802.11ac infrastructure mode of operation or
a similar mode of operations, the AP may transmit a beacon on a
fixed channel, such as a primary channel. The primary channel may
be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set
width. The primary channel may be the operating channel of the BSS
and may be used by the STAs to establish a connection with the AP.
In certain representative embodiments, Carrier Sense Multiple
Access with Collision Avoidance (CSMA/CA) may be implemented, for
example in 802.11 systems. For CSMA/CA, the STAs (e.g., every STA),
including the AP, may sense the primary channel. If the primary
channel is sensed/detected and/or determined to be busy by a
particular STA, the particular STA may back off. One STA (e.g.,
only one station) may transmit at any given time in a given
BSS.
[0054] High Throughput (HT) STAs may use a 40 MHz wide channel for
communication, for example, via a combination of the primary 20 MHz
channel with an adjacent or nonadjacent 20 MHz channel to form a 40
MHz wide channel.
[0055] Very High Throughput (VHT) STAs may support 20 MHz, 40 MHz,
80 MHz, and/or 160 MHz wide channels. The 40 MHz, and/or 80 MHz,
channels may be formed by combining contiguous 20 MHz channels. A
160 MHz channel may be formed by combining 8 contiguous 20 MHz
channels, or by combining two non-contiguous 80 MHz channels, which
may be referred to as an 80+80 configuration. For the 80+80
configuration, the data, after channel encoding, may be passed
through a segment parser that may divide the data into two streams.
Inverse Fast Fourier Transform (IFFT) processing, and time domain
processing, may be done on each stream separately. The streams may
be mapped on to the two 80 MHz channels, and the data may be
transmitted by a transmitting STA. At the receiver of the receiving
STA, the above described operation for the 80+80 configuration may
be reversed, and the combined data may be sent to the Medium Access
Control (MAC).
[0056] Sub 1 GHz modes of operation are supported by 802.11af and
802.11ah. The channel operating bandwidths, and carriers, are
reduced in 802.11af and 802.11ah relative to those used in 802.11n,
and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz
bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah
supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using
non-TVWS spectrum. According to a representative embodiment,
802.11ah may support Meter Type Control/Machine-Type Communications
(MTC), such as MTC devices in a macro coverage area. MTC devices
may have certain capabilities, for example, limited capabilities
including support for (e.g., only support for) certain and/or
limited bandwidths. The MTC devices may include a battery with a
battery life above a threshold (e.g., to maintain a very long
battery life).
[0057] WLAN systems, which may support multiple channels, and
channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and
802.11ah, include a channel which may be designated as the primary
channel. The primary channel may have a bandwidth equal to the
largest common operating bandwidth supported by all STAs in the
BSS. The bandwidth of the primary channel may be set and/or limited
by a STA, from among all STAs in operating in a BSS, which supports
the smallest bandwidth operating mode. In the example of 802.11ah,
the primary channel may be 1 MHz wide for STAs (e.g., MTC type
devices) that support (e.g., only support) a 1 MHz mode, even if
the AP, and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16
MHz, and/or other channel bandwidth operating modes. Carrier
sensing and/or Network Allocation Vector (NAV) settings may depend
on the status of the primary channel. If the primary channel is
busy, for example, due to a STA (which supports only a 1 MHz
operating mode) transmitting to the AP, all available frequency
bands may be considered busy even though a majority of the
available frequency bands remains idle.
[0058] In the United States, the available frequency bands, which
may be used by 802.11ah, are from 902 MHz to 928 MHz. In Korea, the
available frequency bands are from 917.5 MHz to 923.5 MHz. In
Japan, the available frequency bands are from 916.5 MHz to 927.5
MHz. The total bandwidth available for 802.11ah is 6 MHz to 26 MHz
depending on the country code.
[0059] FIG. 1D is a system diagram illustrating the RAN 104 and the
CN 106 according to an embodiment. As noted above, the RAN 104 may
employ an NR radio technology to communicate with the WTRUs 102a,
102b, 102c over the air interface 116. The RAN 104 may also be in
communication with the CN 106.
[0060] The RAN 104 may include gNBs 180a, 180b, 180c, though it
will be appreciated that the RAN 104 may include any number of gNBs
while remaining consistent with an embodiment. The gNBs 180a, 180b,
180c may each include one or more transceivers for communicating
with the WTRUs 102a, 102b, 102c over the air interface 116. In one
embodiment, the gNBs 180a, 180b, 180c may implement MIMO
technology. For example, gNBs 180a, 108b may utilize beamforming to
transmit signals to and/or receive signals from the gNBs 180a,
180b, 180c. Thus, the gNB 180a, for example, may use multiple
antennas to transmit wireless signals to, and/or receive wireless
signals from, the WTRU 102a. In an embodiment, the gNBs 180a, 180b,
180c may implement carrier aggregation technology. For example, the
gNB 180a may transmit multiple component carriers to the WTRU 102a
(not shown). A subset of these component carriers may be on
unlicensed spectrum while the remaining component carriers may be
on licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c
may implement Coordinated Multi-Point (CoMP) technology. For
example, WTRU 102a may receive coordinated transmissions from gNB
180a and gNB 180b (and/or gNB 180c).
[0061] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a,
180b, 180c using transmissions associated with a scalable
numerology. For example, the OFDM symbol spacing and/or OFDM
subcarrier spacing may vary for different transmissions, different
cells, and/or different portions of the wireless transmission
spectrum. The WTRUs 102a, 102b, 102c may communicate with gNBs
180a, 180b, 180c using subframe or transmission time intervals
(TTIs) of various or scalable lengths (e.g., containing a varying
number of OFDM symbols and/or lasting varying lengths of absolute
time).
[0062] The gNBs 180a, 180b, 180c may be configured to communicate
with the WTRUs 102a, 102b, 102c in a standalone configuration
and/or a non-standalone configuration. In the standalone
configuration, WTRUs 102a, 102b, 102c may communicate with gNBs
180a, 180b, 180c without also accessing other RANs (e.g., such as
eNode-Bs 160a, 160b, 160c). In the standalone configuration, WTRUs
102a, 102b, 102c may utilize one or more of gNBs 180a, 180b, 180c
as a mobility anchor point. In the standalone configuration, WTRUs
102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using
signals in an unlicensed band. In a non-standalone configuration
WTRUs 102a, 102b, 102c may communicate with/connect to gNBs 180a,
180b, 180c while also communicating with/connecting to another RAN
such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b,
102c may implement DC principles to communicate with one or more
gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c
substantially simultaneously. In the non-standalone configuration,
eNode-Bs 160a, 160b, 160c may serve as a mobility anchor for WTRUs
102a, 102b, 102c and gNBs 180a, 180b, 180c may provide additional
coverage and/or throughput for servicing WTRUs 102a, 102b,
102c.
[0063] Each of the gNBs 180a, 180b, 180c may be associated with a
particular cell (not shown) and may be configured to handle radio
resource management decisions, handover decisions, scheduling of
users in the UL and/or DL, support of network slicing, DC,
interworking between NR and E-UTRA, routing of user plane data
towards User Plane Function (UPF) 184a, 184b, routing of control
plane information towards Access and Mobility Management Function
(AMF) 182a, 182b and the like. As shown in FIG. 1D, the gNBs 180a,
180b, 180c may communicate with one another over an Xn
interface.
[0064] The CN 106 shown in FIG. 1D may include at least one AMF
182a, 182b, at least one UPF 184a, 184b, at least one Session
Management Function (SMF) 183a, 183b, and possibly a Data Network
(DN) 185a, 185b. While the foregoing elements are depicted as part
of the CN 106, it will be appreciated that any of these elements
may be owned and/or operated by an entity other than the CN
operator.
[0065] The AMF 182a, 182b may be connected to one or more of the
gNBs 180a, 180b, 180c in the RAN 104 via an N2 interface and may
serve as a control node. For example, the AMF 182a, 182b may be
responsible for authenticating users of the WTRUs 102a, 102b, 102c,
support for network slicing (e.g., handling of different protocol
data unit (PDU) sessions with different requirements), selecting a
particular SMF 183a, 183b, management of the registration area,
termination of non-access stratum (NAS) signaling, mobility
management, and the like. Network slicing may be used by the AMF
182a, 182b in order to customize CN support for WTRUs 102a, 102b,
102c based on the types of services being utilized WTRUs 102a,
102b, 102c. For example, different network slices may be
established for different use cases such as services relying on
ultra-reliable low latency (URLLC) access, services relying on
enhanced massive mobile broadband (eMBB) access, services for MTC
access, and the like. The AMF 182a, 182b may provide a control
plane function for switching between the RAN 104 and other RANs
(not shown) that employ other radio technologies, such as LTE,
LTE-A, LTE-A Pro, and/or non-3GPP access technologies such as
WiFi.
[0066] The SMF 183a, 183b may be connected to an AMF 182a, 182b in
the CN 106 via an N11 interface. The SMF 183a, 183b may also be
connected to a UPF 184a, 184b in the CN 106 via an N4 interface.
The SMF 183a, 183b may select and control the UPF 184a, 184b and
configure the routing of traffic through the UPF 184a, 184b. The
SMF 183a, 183b may perform other functions, such as managing and
allocating UE IP address, managing PDU sessions, controlling policy
enforcement and QoS, providing DL data notifications, and the like.
A PDU session type may be IP-based, non-IP based, Ethernet-based,
and the like.
[0067] The UPF 184a, 184b may be connected to one or more of the
gNBs 180a, 180b, 180c in the RAN 104 via an N3 interface, which may
provide the WTRUs 102a, 102b, 102c with access to packet-switched
networks, such as the Internet 110, to facilitate communications
between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF
184, 184b may perform other functions, such as routing and
forwarding packets, enforcing user plane policies, supporting
multi-homed PDU sessions, handling user plane QoS, buffering DL
packets, providing mobility anchoring, and the like.
[0068] The CN 106 may facilitate communications with other
networks. For example, the CN 106 may include, or may communicate
with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server)
that serves as an interface between the CN 106 and the PSTN 108. In
addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with
access to the other networks 112, which may include other wired
and/or wireless networks that are owned and/or operated by other
service providers. In one embodiment, the WTRUs 102a, 102b, 102c
may be connected to a local DN 185a, 185b through the UPF 184a,
184b via the N3 interface to the UPF 184a, 184b and an N6 interface
between the UPF 184a, 184b and the DN 185a, 185b.
[0069] In view of FIGS. 1A-1D, and the corresponding description of
FIGS. 1A-1D, one or more, or all, of the functions described herein
with regard to one or more of: WTRU 102a-d, Base Station 114a-b,
eNode-B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-b,
UPF 184a-b, SMF 183a-b, DN 185a-b, and/or any other device(s)
described herein, may be performed by one or more emulation devices
(not shown). The emulation devices may be one or more devices
configured to emulate one or more, or all, of the functions
described herein. For example, the emulation devices may be used to
test other devices and/or to simulate network and/or WTRU
functions.
[0070] The emulation devices may be designed to implement one or
more tests of other devices in a lab environment and/or in an
operator network environment. For example, the one or more
emulation devices may perform the one or more, or all, functions
while being fully or partially implemented and/or deployed as part
of a wired and/or wireless communication network in order to test
other devices within the communication network. The one or more
emulation devices may perform the one or more, or all, functions
while being temporarily implemented/deployed as part of a wired
and/or wireless communication network. The emulation device may be
directly coupled to another device for purposes of testing and/or
performing testing using over-the-air wireless communications.
[0071] The one or more emulation devices may perform the one or
more, including all, functions while not being implemented/deployed
as part of a wired and/or wireless communication network. For
example, the emulation devices may be utilized in a testing
scenario in a testing laboratory and/or a non-deployed (e.g.,
testing) wired and/or wireless communication network in order to
implement testing of one or more components. The one or more
emulation devices may be test equipment. Direct RF coupling and/or
wireless communications via RF circuitry (e.g., which may include
one or more antennas) may be used by the emulation devices to
transmit and/or receive data.
[0072] Wireless transmissions that provide enhanced throughput,
enhanced reliability, reduced latency and jitter, and improved
power efficiency in many usage scenarios are disclosed herein.
Applications that may be supported by such attributes include, but
are not limited to, 4K/8K videos, gaming, virtual and augmented
reality, remote office environments, cloud computing, etc. New
generation WLAN devices may provide support to such applications
that require very low latency as well as applications that require
high throughput and high spectral efficiency. 4K/8K video, gaming,
augmented reality, virtual reality, remote office environments,
could computing, and the like are examples of applications of next
generation WLAN which require low-latency communications.
[0073] Latency may be identified as a requirement since new,
high-throughput, low latency applications, such as virtual reality,
gaming, remote office, and cloud computing, will proliferate.
Traffic growth for such and like applications continues to be
driven by a significant growth in the video traffic and that IP
video traffic. The throughput requirements of these and like
application is in constant evolution with the emergency of 4K and
8K video, and new high-throughput applications such as virtual
reality, gaming, remote office, and cloud computing. With the
throughput and real-time requirements of these applications, WLAN
users demand improved throughput and performance in delivering
their applications in many environments.
[0074] 5G NR networks may be designed to support three service
categories: emBB, massive machine type communication (mMTC), and
URLLC. Mechanisms and procedures designed for URLLC provide
advanced services for latency sensitive devices or traffic.
Configure grant transmission is adopted to reduce the frame
exchanges of service request/response between gNB and WTRUs, so
that WTRUs with low latency traffics are able to transmit them in
pre-configured resources without requesting transmissions.
[0075] In WLAN, CSMA/CA channel access is used for multiple access.
An STA can transmit without approval from its associated AP when
the STA listens to the shared medium for a certain period and
determines medium is free. The channel sensing resolution is
typically 20 MHz or above.
[0076] In IEEE 802.11ax, OFDMA is adopted for both DL and UL
transmission. Mechanisms and procedures are defined to enable one
or more STAs to concurrently transmit in different frequency units.
Normally, the concurrent UL OFDMA transmissions can be triggered
and scheduled by the associated AP. Two schemes can be supported
for low latency transmissions: UL OFDMA based Random Access (UORA)
for associated and non-associated STAs; and Null Data Packet (NDP)
feedback report procedure.
[0077] In IEEE 802.11ax, am STA can perform autonomous UL
transmission using either traditional CSMA/CA procedure by sensing
the entire channel or UORA. An AP may transmit a trigger frame with
a set of resource units for associated STAs and/or unassociated
STAs to transmit UL traffic. The AP may assign uplink MCS, length,
and other related physical parameters. An STA may use a UORA
procedure to determine the resource and transmit triggers based
physical layer convergence protocol (PLOP) protocol data unit
(PPDU). The AP transmits acknowledgement, such as multi-STA BA to
the STAs. An example trigger frame format is shown in Table 1.
TABLE-US-00001 TABLE 1 Frame Control Duration RA TA Common Info
User Info . . . User Info Padding FCS 2 2 6 6 8 or more 5 or more 5
or more v 4
[0078] An example common information field is shown in Table 2.
TABLE-US-00002 TABLE 2 # of HE-LTF GI and MU-MIMO Symbols and
Common Trigger UL More CS UL LTF LTF Midamble Info Type Length TF
Required BW Type Mode Periodicity Bits 4 12 1 1 2 2 1 3 LDPC
Trigger Extra AP Pre-FEC UL UL HE Dependent UL Symbol TX Padding PE
Spatial SIG-A2 Common STBC Segment Power Factor Disambiguity Reuse
Doppler Reserved Reserved Info 1 1 6 2 1 16 1 9 1 v
[0079] An example user information field in trigger frame, except
for NFRP Trigger, is shown in Table 3.
TABLE-US-00003 TABLE 3 SS User Info UL Allocation/ UL Trigger (not
for RU FEC UL UL RA-RU Target Dependent NFRP) AID12 Allocation
Coding MCS DCM Information RSSI Reserved User Info Bits 12 8 1 4 1
6 7 1 v
[0080] In IEEE 802.11ax, an NDP feedback report procedure is
supported. First, an AP may transmit a NDP Feedback Report Poll
(NFRP) Trigger, in which the AP may indicate that feedback type is
a resource request. A starting association ID (AID) field may be
included in the trigger frame. Next, an STA may receive and/or
detect the NFRP Trigger to determine if it is scheduled and how to
transmit its NDP feedback report in response to the NFRP trigger.
The STA may obtain an NDP feedback report parameter from management
frames. The STA may follow the instructions in the NFRP Trigger and
the NDP feedback report parameter to transmit the NDP feedback
report. The NDP feedback report may be received by the AP. No
acknowledge may be sent from the AP to the STAs. A trigger frame
for NFRP may be in the frame format shown in Table 1.
[0081] A common information field for NFRP may be in the same
format shown in Table 2.
[0082] An example user information field for NFRP is shown in Table
4.
TABLE-US-00004 TABLE 4 User Info Starting Feedback UL Target
Multiplexing (NFRP) AID Reserved Type Reserved RSSI Flag Bits 12 9
4 7 7 1
[0083] An STA triggered by an AP may respond with a trigger based
PPDU. An example trigger based PPDU format is shown in Table 5.
TABLE-US-00005 TABLE 5 L-STF L-LTF L-SIG RL-SIG HE-SIG-A HE-STF
HE-LTF . . . HE-LTF Data PE
[0084] Transmissions in response to a UORA trigger may be
transmitted with a single data stream.
[0085] Lower latency uplink transmissions can be supported by a
fast exchange of resource requests and/or responses between an AP
and one or more STAs. During a NDP feedback report procedure, an AP
may transmit an NDP feedback report poll (NFRP) trigger, in which
the AP may indicate that feedback type is a resource request. A
starting association ID (AID) field may be included in the trigger
frame sent by the AP. Next, an STA may receive and/or detect the
NFRP trigger to determine if it is scheduled and how to transmit
its NDP feedback report. The STA may obtain an NDP feedback report
parameter from management frames. No acknowledge may be sent from
the AP to the STAs.
[0086] However, the NDP feedback report procedure may not be
sufficient for certain low latency applications. For example, an AP
may trigger a set of STAs with continuous AIDs, within an AID
range, to transmit a resource request. However, a STA which is not
in the AID range cannot be used to transmit a resource request or
NDP feedback report. Further, a feedback status carried in the in
the NDP feedback report may only signal the buffer size roughly in
bytes. No latency or other quality of service (QoS) requirements
may be included.
[0087] FIG. 2 shows an example NDP feedback report procedure as
described herein. An AP may transmit a NDP Report Poll 210 to a
plurality of STAs such that the NDP Report Poll 210 that triggers a
UL NDP feedback report from STAs with AIDs K through K+N. NDP
reports 220 from the N+1STAs may be generated, as shown, and may
include a first part 222 that comprises a PHY header and a second
part 224 that comprises long training fields (LTFs) that can hold
one bit of information. As shown, an NDP report is generated by
each STA sequenced from 226K through 226K+N. Notably, in the
example shown in FIG. 2, an NDP report from the N+1 STAs may only
include the first part 222 that comprises the PHY header and only a
single bit for LTF information. Accordingly, according to the NDP
feedback report procedure, an entire sequential range of STAs
(e.g., K through K+N) respond to an NDP report poll and, further,
each STA provides one bit of data. The one bit of data may indicate
whether buffered payload at the STA is either greater than or less
than a threshold (e.g., a pre-determined threshold or a dynamically
determined threshold). Accordingly, the NDP feedback report
procedure may return sequential STA data and each STA may indicate
whether a buffered payload is greater than or less than a given
threshold.
[0088] According to embodiments of the disclosed subject matter, UL
resource requests may be triggered for low latency traffic. FIG. 3
shows an example method for low latency resource request indication
and trigger based uplink transmissions. As shown in FIG. 3, an AP
may provide a random trigger to trigger resource request at 310 and
may receive a number of NDP reports 320. The AP may transmit
scheduled triggers at 330 based on the NDP reports for resource
request at 320. The STAs may transmit data 340 based on the
scheduled triggers 330.
[0089] An AP may transmit a resource request poll that solicits
resource requests from STAs that are associated with the AP. For
example, the AP may indicate, via the trigger frame, that it is
soliciting compact resource requests, such as NDP feedback reports.
The resource request poll may be an NFRP, a variation of an NFRP,
or the like. The resource request poll (e.g., NFRP) may include one
or more information types including, but not limited to, NFRP type,
UL access type, delay bound, NDP feedback report AC, number of
indicated AID bits, AID ranges, information requested, number of
bits to be included in NDP feedback report or preamble, number of
long training fields (LTFs) to be included in the NDP feedback
report or preamble, and number of bits to be included in NDP
feedback report or preamble per LTF or per N LTF symbol. One or
more of the information types may be included in the reserved bits
in the NFRP trigger frame. The one or more information types may
generally be referred to as "response criteria" herein.
[0090] An NFRP type may indicate the type of the trigger of NFRP.
For example, it may indicate that a given NFRP or trigger frame is
triggering resource request for low latency traffic, or for all
traffic.
[0091] A UL access type may indicate the type of UL access when
STAs are triggered to transmit UL data or resource requests. The UL
access type may be random or deterministic. If deterministic, an
STA may follow the indicated AID range or order to transmit their
UL data or resource request on the deterministic resource units
(RUs) or subchannels. If random, the STAs may randomly choose an
RU, following the indicated AID range, or order to transmit their
UL data or resource request.
[0092] A delay bound may include information regarding a given
delay bound associated with the resource request poll (e.g., NRFP).
A delay bound may be, for example, an amount of time such that an
STA may respond to a resource request poll if it requires a UL
transmission within the amount of time of the delay bound. If an
STA has traffic that needs to be transmitted to the AP before the
given delay bound is expired, it may respond to the NFRP or trigger
frame with a resource request. For example, the NFRP may include a
delay bond of 20 ms such that STAs that require a UL transmission
within the 20 ms respond to the NFRP and STAs that do not require a
UL transmission within that time period may not respond to the
NFRP. The delay bound may be specified as related to the time of
transmission of the trigger frame or NFRP. Therefore, the UL
traffic may be transmitted within the delay bound starting at the
beginning or end of the NFRP or trigger frame that is being
transmitted or related to the traffic specification. For example,
the UL transmission may be transmitted within the delay bound
specified counting from the time of generation or reception or from
the time it has entered the queue.
[0093] An NDP feedback report access category (AC) includes access
category restrictions for the solicited NDP feedback report or
resource request. In embodiments, the AC values may be Low Latency,
best effort (BK), background (BC), video (VI), and voice (VO). Low
Latency AC may be ranked higher than VI and VO. A bit map may be
used in an NFRP or trigger to indicate triggering of resource
request for one or more ACs. If the NFRP or trigger frame
triggering resource request is for a particular AC, the STA may
indicate in the resource request all traffics for the ACs that is
higher or equal to the indicated AC. In embodiments, the STA may
indicate in the triggered resource request the traffic associated
with the indicated AC. Additionally, the STA may use a bit map to
indicate the presence or priorities for a plurality of ACs, as
further disclosed herein under the information requested category.
For example, a resource request in response to an NFRP or trigger
may include four LTF bits, each corresponding to an AC (e.g., Low
Latency, VO, VI, BC) such that the value for each bit in a resource
request may indicate whether the given STA has a payload to
transmit for the corresponding AC or to indicate a given property
of the corresponding AC payload (e.g., priority).
[0094] A number of indicated AID bits indicates how many bits of
the AID, such as the number of most significant bits (MSBs) or
least significant bits (LSBs) of the AIDs, are indicated in the
current trigger frame or NFRP frame. The number of bits of AID,
such as MSBs, may be used to indicate the ranges of AIDs for which
resource request is being triggered. For example, if 6 bits of MSBs
or LSBs of AIDs are indicated in the trigger or NFRP frame, all
STAs with AIDs that start with the 6 bits of MSBs or ends with the
6 bits of LSBs are to respond with resource request if they satisfy
other requirements indicated by the trigger or NFRP frames.
[0095] AID ranges indicate one or more AID ranges of STAs that the
NFRP or trigger frame is triggering the UL resource request. AID
ranges may be in the form of a number of indicated MSBs or LSBs of
AID bits and may be implemented by the combinations of STAs
starting with given AID and/or a number of AIDs. Notably, a number
or range of non-sequential STAs (i.e., with corresponding
non-sequential STA AIDs) may be included via a given AID range or
AID ranges such that non-sequential STAs transmit resource
requests. Such non-sequential resource requests may allow greater
flexibility than a single range of AIDs, as shown in FIG. 2.
[0096] Information requested indicates the feedback (e.g., ACs,
priority, size, etc.) that the polled STAs may indicate in the
triggered UL data transmission, resource request, or NDP feedback.
The information may be indicated as a bitmap. For example, the
information requested may be for one or more low latency traffic
streams. The information requested may be for one or more ACs.
Alternative or in addition, the information requested may be the
queue size for one or more traffic streams, or ACs.
[0097] A number of bits to be included in NDP feedback report or
preamble indicates the number of bits that should be included in
the triggered NDP feedback report or triggered preambles or
triggered UL transmissions. The number of bits may be contained or
encoded in the legacy preambles, HE or EHT preambles, such as HE-
or EHT-LTFs and HE- or EHT-STFs or other fields, the MAC header,
the frame body, or the CRC or FCS fields.
[0098] The number of LTFs to be included in the triggered NDP
feedback report or preamble may indicate the number of HE- or
EHT-LTFs to be included in the NDP feedback report, preambles, or
triggered resource requests. The number may indicate the number of
LTFs or number of LTF pairs that the STA should transmit in the
UL/resource request in response to a current trigger or NFRP
frame.
[0099] The number of bits to be included in NDP feedback report or
preamble per LTF, per 2, or per N LTF symbol may indicate the
number of bits for an STA to include per HE- or EHT-LTFs, per 2, or
per N HE- or EHT-LTFs when transmitting the triggered NDP feedback
report or resource request. The number of bits may be implemented
using less subcarriers for each bit per 1, 2, N HE or EHT-LTFs, or
other fields.
[0100] According to embodiments of the disclosed subject matter,
all or a subset of the information types described herein may be
included in a NDP Feedback Report Parameter Set element or other
type of element or frames transmitted by the AP. An NDP Feedback
Report Parameter Set element or other type of element, frames
transmitted by the AP, and/or a Short Resource Request poll, may be
generally and collectively referred to as a "resource request
poll". Additionally, a UL data transmission, resource request, NDP
feedback report, a Short report (e.g., a UL Low Latency Short
report), and/or Short Resource Request may generally and
collectively be referred to as a "resource request report". As
disclosed herein, a request poll may be transmitted by an AP and
may be received by one or more STAs such that the resource request
poll may trigger the one or more STAs to generate and transmit a
resource request report.
[0101] FIG. 4 shows an example process 400 for implementing AP and
STA based transmission procedures. It will be understood that the
steps provided in process 400 may not be performed in a sequential
order and, further, one or more steps may not be performed to
implement the embodiments disclosed herein. An AP may conduct
association with one or more STAs and may provide one or more
information types disclosed herein via an element such as an NDP
Feedback Report Parameter Set element or other applicable element.
The association process may be initiated by the one or more STAs.
The AP may provide the one or more information types, via an
element, during an association process with one or more STAs or in
their respective beacon, short beacon, probe response frames, FILS
Discovery frames, or association response frames.
[0102] At 404, an STAs may conduct the association process with the
AP and may indicate that one or more of the STAs has low latency
traffic, during the association process with the AP. The STA may
also indicate AP that it has low latency traffic or one or more low
latency data streams using a traffic specification (TSPEC) or a low
latency request frame.
[0103] At 406, an STA may be assigned one or more target wake up
times (TWT). For example, the STA may be assigned a broadcast TWT
or service periods in which it is polled for UL low latency data
transmission or UL low latency resource request. It will be
understood that any part of process 400, such as 406 is optional
such that the process 400 may be implemented without performing 406
or 406 may be performed in an alternative order than the order
provided herein.
[0104] At 408, at any given time or at a previously agreed service
period, such as a broadcast or individual TWT service period, the
AP may poll the one or more STAs via a resource request poll. The
resource request pool may indicate response criteria and one or
more STA's IDs. For example, the AP may include one or more AID
ranges in a trigger frame or in NFRP frames.
[0105] To indicate a particular AID range, the AP may indicate a
starting AID, as well as a number of AIDs to indicate a particular
range of AIDs. Alternatively, the AP may indicate the number of AID
bits used in the trigger or NFRP frame to indicate a range. For
example, the trigger frame or NFRP may include an indication of a
number N of MSBs or LSBs of an AID range. Accordingly, the AID
range would correspond to all STAs with AIDs that contained the N
MSBs or LSBs.
[0106] As noted, at 408 the AP may send a frame (e.g., resource
request poll, trigger frame or NFRP frame to poll STAs for UL
resource request). The resource request poll to poll STAs may be
sent at any given time period or at a previously agreed service
period, such as a broadcast or individual TWT service period.
Further, AP may indicate the information type required in response
to the resource request poll such as a particular type of traffic
being polled, such as low latency traffic, or one or more
particular ACs, such as low latency, low latency VR, low latency
AR, low latency gaming, BK, BE, VO and VI.
[0107] Additionally, at 408, the AP resource request poll's
response criteria may specify the delay bound for traffic being
polled, such as frames that need to be transmitted within the
indicated delay bound. A resource request poll with a specific
delay bound may be interpreted as a poll requesting all traffic
that needs to be transmitted within the delay bound. For example,
if the delay bound is 10 ms, the traffic being polled may include a
VO frame that was generated 44 ms before the poll is received at
the FTA, and needs to be transmitted within a 50 ms delay bound
from generation. Accordingly, the VO frame satisfies the 10 ms
delay bound requirement as it needs to be transmitted within Ems
from receipt of the poll. As another example, traffic qualifying
for the 10 ms delay bound requirement may also include low latency
traffic that was generated 4 ms before the poll is received, and is
to be transmitted to the AP with a 10 ms delay from generation.
According to an embodiment, a resource request poll with the
indicated delay bound may be interpreted as including traffic to be
delivered within a delay bound that is lower or equal to the
specific indicated delay bound since the generation of the given
traffic. An STA being polled (e.g., whose AID is indicated in the
trigger frame or NFRP) may respond, if it satisfies other
requirements, such as if the STA has traffic or traffic streams
that satisfy the delay bound requirement by transmitting a NDP
feedback report or a UL resource request or data.
[0108] Additionally, at 408, the AP may indicate that the resource
request report or specifically a UL transmission be transmitted
randomly or deterministically. If the resource request report or UL
transmission is to be transmitted deterministically, resources may
be allocated for each of the AID ranges provided by the AP at 412.
Further resources may be allocated for each of the AID ranges while
indicating multiplexing by using P matrices or other methods for
each of the AID ranges associated with a given resource allocation.
If the resource request report or UL transmission are to be
transmitted randomly, resources may be allocated for each of the
AID ranges. Additionally or alternatively, the trigger frame or
NFRP may also contain the number of bits N that the responding STAs
may include in the UL data transmission or resource request. The
responding STAs may include the number of bits as indicated in the
trigger frame or NFRP, which may be N bits of MSB or LSB of an
STA's AID (i.e., to indicate their identity), such as in the number
of LTFs or number of pair of LTFs fields to be included. For
example, a AP may indicate an AID range by indicating 6 MSBs of the
AID range to poll all STAs whose AIDs contain the 6 MSBs in their
AIDs. The AP may also indicate that the STA should include 5 LSBs
in their responding data transmission or resource request frames,
e.g., NDP feedback report. The responding STAs may include the
number of HE- or EHT-LTFs in the resource request or NDP feedback
report, which may be 5 or 10 HE- or EHT-LTFs. The 5 or 10 HE- or
EHT-LTFs may include the 5 LSBs of its AID in the UL transmitted
data transmission or resource request of NDP feedback report. The
resource request report may be transmitted randomly over the
resource allocated for the corresponding AID range.
[0109] At 410, an STA may determine whether it is polled by the AP.
An STA may determine whether it is polled based on, for example, if
its AID is included in one or more of the AID ranges, as indicated
by the AP in the trigger frame or NFRP.
[0110] Additionally, the STA being polled (e.g., an STA with an AID
that was indicated in the trigger frame or NFRP) may respond via a
resource request report, at 412, if it satisfies other requirements
of the received resource request poll, such as if the STA has low
latency or the right type of low latency traffic, or traffic of the
indicated AC by transmitting an NDP feedback report or a UL
resource request or data. Additionally or alternatively, an STA
being polled may respond if it satisfies other requirements, such
as if the STA has low latency or the right type of low latency
traffic, or traffic of the indicated AC, or higher, that is above a
certain threshold which may be indicated by the NDP Feedback Report
Parameter Set element by transmitting a NDP feedback report or a UL
resource request or data.
[0111] At 414, an AP may identify which one or more STAs, of a
plurality of STAs, have requested resources by examining the N bits
included in the respective resource request reports (e.g., UL data
transmission, resource request, or NDP feedback report). The AP may
identify the AID of the requesting STA and, at 416, subsequently
transmit a trigger frame to the STA to trigger UL data
transmissions. If two STAs have chosen the same resource or RU for
uplink transmissions of resource request or NDP feedback report,
the AP may detect collision. The AP may allocate a number of random
access RU or resources to trigger subsequent data transmission
using one or more AID ranges, for an RU index at which the
collision occurred for UL resource request to accommodate the STAs
that collided, when transmitting the UL resource request. The
process 400 of FIG. 4 may enable an AP to access information
corresponding to the current transmission requirements of
associated STAs.
[0112] According to an embodiment, an AP may indicate information
requested from the STAs, such as bitmap for one or more low latency
data streams, for one or more access categories, or for one or more
type of low latency data or other type of data, as disclosed
herein. The AP may request that the STAs provide more detailed size
information regarding the information requested, such as sizes of
queues and/or low latency data or other type of data or access
categories. The AP may indicate how many bits that a polled STA may
include in the responding or triggered data transmission, resource
request, or NDP feedback report. Such information may be included
in the Number of Bits to be included field, Number of LTFs, or
Number of Pair of LTFs to be included information. An STA that is
polled may include the number of bits, number of LTFs, or number of
pair of LTFs in the NDP feedback report or in the resource request
that is being triggered. Each bit may correspond to each bit in the
bitmap for information requested. Additionally or alternatively,
the STAs that are polled may transmit the triggered resource
request or NDP report and may use the number of bits as indicated
by the AP to indicate the size of queues of data streams or low
latency traffics. As noted herein, it will be understood that any
part of process 400, such as 416 is optional such that the process
400 may be implemented without performing 416 or 416 may be
performed in an alternative order than the order provided
herein.
[0113] FIG. 5 shows a diagram showing a resource request procedure
500 and includes a resource request poll 510 and resource request
report 530, as disclosed herein. As shown in FIG. 5, a resource
request poll 510 may be generated by an AP and may be transmitted
(e.g., via broadcast or multicast) to one or more STAs. The
resource request poll 510 may be a NDP Feedback Report Parameter
Set element or other type of element or frame. As disclosed herein,
an AP may be associated with one or more STAs (e.g., during a
beacon period). The resource request poll 510 may be generated at
the AP and transmitted to and/or received by one or more associated
STAs.
[0114] As shown in FIG. 5, the resource request poll 510 may
include response criteria 512 which includes a delay bound 514 and
QoS priorities 516. It will be understood that the low latency
criteria 512 may include one or more other or alternative
information types including, but not limited to, NFRP type, UL
access type, NDP feedback report AC, number of indicated AID bits,
AID ranges, information requested, or the like. Additionally, it
will be understood that the response criteria 512 may correspond to
low latency response criteria such that STAs that meet the response
criteria 512 may have low latency data to transmit. Additionally,
the resource request poll 510 may include a Number of Bits field
518 for traffic indication N. The number of bits field 518 may
include a number of bits to be included in a requested resource
report such as an NDP feedback report or preamble, number of long
training fields (LTFs) to be included in the NDP feedback report or
preamble, and number of bits to be included in NDP feedback report
or preamble per LTF or per N LTF symbol, a bitmap of AC based
priority data, or the like.
[0115] The resource request poll 510 may be transmitted by the AP
and received by one or more STAs. The one or more STAs may each
determine if they meet the response criteria 512. STAs that meet
the response criteria 512 may each generate a resource request
report (e.g., resource request report 532, 534, and 536) as shown
by the set of generated resource request reports 530. The generated
resource requests reports 530 may each include a first part PHY
header 540 and a number of N bits 541, as provided in the
corresponding resource request poll 510. The N bits 541 may each
include 1 bit of data that corresponds to, for example, a detailed
indication of size for the data to be transmitted by a respective
STA to the AP or to provide a bitmap for request of more than 1
traffic priorities (e.g., VO, VI, BC, BK). As examples of
information provided by the N bits 541, each of a number of bits in
the N bits 541 may be used to indicate different priorities for
different AC (e.g., VO, VI, BC, BK). Alternatively, for example, a
plurality of the N bits 541 may be used to indicate how much of a
given priority AC that the STA is to transmit. Alternatively, for
example, some of the N bits 541 may be used to provide STA
identification information.
[0116] The AP may receive the resource request reports 530 from
each STA that meets the response criteria 512. Based on the
resource request reports 530, the AP may determine a priority order
to trigger UL data transmissions from the STAs that transmitted the
resource request reports 530.
[0117] Notably, based on the techniques disclosed herein, an AP may
poll a number of STAs that may not be sequential such as APs having
different ranges. As an example, FIG. 5 shows a resource request
report 532 for STA 2 followed by resource request report 536 for
STA 6 (i.e., STA 2 and STA 6 do not have sequential AIDs).
Additionally, STAs may provide detailed information based on the
AP's resource request poll 510's number of bits 518 indication, as
disclosed herein.
[0118] According to an embodiment, an AP may maintain a separate
low latency ID bitmap for STAs that currently have low latency
traffic. An AP may advertise that it supports low latency
transmissions by including a low latency element in its beacon,
short beacon, FILS Discovery frames, probe response, or association
response frames. The low latency element may include an indication
that it supports low latency bitmaps. When an STA seeking
association with an AP has low latency traffic or low latency
traffic streams, it may also include a low latency element in its
probe request or association request frames. The STA may include an
indication of support of low latency ID bitmap in the low latency
element. If an STA that is already associated with an AP starts a
low latency traffic stream, it may send a low latency request frame
which may include the low latency element to request a low latency
ID. The AP may assign a low latency ID to the STA in response to
the low latency request frame or associated response frame. For
example, the AP may include a low latency assignment element in the
association response frame or in the low latency response frame
which may include a low latency ID and/or TWT information.
[0119] A low latency ID may be an ID that is assigned to an STA.
Alternatively or in addition, the AP may assign a low latency ID to
each low latency data stream indicated by the STA. Alternatively or
in addition, the AP may allocate a separate section of the AID
space to the low latency IDs or low latency IDs for certain type of
application(s), such as virtual reality. Each of the separate
sections may be identified by a common number of bits of MSBs or
LSBs of the AID space. For example, a low latency ID range may be
identified as a range of AIDs that all start with the same 6 bits
of MSBs. An AP may assign an individual low latency ID for each of
the low latency traffic streams.
[0120] Low latency data streams may be polled for UL transmission
or resource request during one or more TWT periods. Alternatively
or in addition, one or more TWT elements may be included in the
association response frame or in the low latency response frame.
Additionally or alternatively, the AP may use low latency broadcast
TWTs to trigger low latency STAs, low latency data stream
transmissions, or low latency resource requests.
[0121] When an STA is assigned one or more low latency IDS and/or
one or more low latency TWTs, the AP may transmit low latency
triggers to trigger low latency STAs, low latency transmissions, or
low latency resource request in the UL. The AP may indicate the ACs
or indicate low latency in such trigger or NFRP frames. If the AP
indicates low latency in such trigger or NFRP frames, it may
include a low latency ID bitmap in the trigger or NFRP frames.
Additionally or alternatively, it may include a range or a number
of ranges of low latency IDs which are being polled. If low latency
IDs are associated with a particular range of AIDs, transmitting a
NFRP, trigger for data, or resource request may imply that the
trigger or NFRP is for low latency traffic.
[0122] Additionally, when an STA is assigned one or more low
latency IDs and/or one or more low latency TWTs, the STA may
monitor the medium for the low latency TWTs or low latency
transmission opportunity (TXOPs) that are assigned to itself for
any UL trigger frames or NFRP frames that are addressed to itself
or addressed to broadcast addresses or group addresses. It may
monitor the low latency IDs that are contained in the NFRP or
trigger frame. If it detects that one or more low latency IDs or
AIDs that are assigned to itself it may respond if it satisfies
other requirements, such as if the STA has low latency or the right
type of low latency traffic, or traffic of the indicated AC by
transmitting a NDP feedback report or a UL resource request or
data.
[0123] An STA may send another Low Latency Request frame or other
type of frames if one or more of its Low Latency traffic or traffic
streams has stopped. The Low latency Request frame may include a
Low Latency element to indicate that one or more its Low Latency
traffic streams have stopped. The Low Latency Request frame or
other type of frames may be used to request that the Low Latency ID
associated with the STA or one or more Low Latency Traffic Type of
Low latency Traffic streams to be removed. The AP may respond with
a Low Latency Response frame or other type of frames to acknowledge
the removal of the Low Latency ID, and/or to confirm one or more
Low latency ID that is still assigned to the STA or associated with
one or more Low Latency Traffic types or streams.
[0124] As disclosed herein, AIDs and low latency IDs are used as
examples. However, any IDs of STAs may be used to indicate an STA,
including MAC addresses or other types of IDs that the AP and STA
have agreed to or otherwise confirmed.
[0125] Although the disclosed subject matter may consider a given
specific protocol (e.g., IEEE 802.11), the embodiments disclosed
herein are not restricted to such a specific protocols, and are
applicable to other wireless systems.
[0126] Although features and elements are described above in
particular combinations, one of ordinary skill in the art will
appreciate that each feature or element can be used alone or in any
combination with the other features and elements. In addition, the
methods described herein may be implemented in a computer program,
software, or firmware incorporated in a computer-readable medium
for execution by a computer or processor. Examples of
computer-readable media include electronic signals (transmitted
over wired or wireless connections) and computer-readable storage
media. Examples of computer-readable storage media include, but are
not limited to, a read only memory (ROM), a random access memory
(RAM), a register, cache memory, semiconductor memory devices,
magnetic media such as internal hard disks and removable disks,
magneto-optical media, and optical media such as CD-ROM disks, and
digital versatile disks (DVDs). A processor in association with
software may be used to implement a radio frequency transceiver for
use in a WTRU, UE, terminal, base station, RNC, or any host
computer.
* * * * *